Secondary alkyl sulfate-containing liquid laundry detergent compositions

ABSTRACT

The present invention relates to a laundry liquid detergent composition comprising from about 1 percent by weight to about 18 percent by weight, basis the total weight of the composition, of one or more secondary alkyl sulfate compounds, from about 6 percent by weight to about 18 percent by weight, basis the total weight of the composition, of one or more additional or cosurfactant compounds, from about 0 percent by weight to about 20 percent by weight, basis the total weight of the composition, of one or more builders, and from about 35 percent by weight to about 78 percent by weight, basis the total weight of the composition, of one or more solvents.

FIELD OF THE INVENTION

The present invention relates to liquid laundry detergent compositionscontaining one or more secondary alkyl sulfate compounds as anionicsurfactant components.

BACKGROUND OF THE INVENTION

Linear alkylbenzene sulfonate (LAS) is one of the most widely usedsurfactants in commerce. It finds special application for light andheavy duty liquid and powdered detergents. A potential disadvantage ofLAS, however, is that under hard water conditions, i.e., calcium levelsgreater than about 150 parts per million, it can interact with cationicwater hardness ions, such as calcium, thereby becoming inactivatedthrough precipitation. While this is a problem common to anionicsurfactants, LAS is especially sensitive to water hardness ions.

Although not wishing to be bound by any theory, the literature indicatesthat the aforementioned interaction can best be understood byconsidering the micellar structure of anionic surfactants, e.g., LAS.Repulsive forces between negative charges in the sulfonate group lead toa higher critical micelle concentration (CMC) than, for example, with anonionic surfactant. CMC is the surfactant concentration at whichmicellar formation begins. Stated otherwise, the negative charge of LASretards micellar formation and shifts the equilibrium towards themonomer. A relatively high monomer concentration in solution resultsthereby; this is significant because precipitation between calcium ionand LAS occurs only with the monomer.

It has been found that liquid laundry detergent compositions containingsecondary alkyl sulfate as an anionic surfactant component can be usedin liquid laundry detergent compositions in place of either LAS orprimary alkyl sulfates with the advantages being increased tolerance forwater hardness ions, good detergency properties, higher active rawmaterial, i.e., less water, and better color of anionic raw material.

SUMMARY OF THE INVENTION

The present invention provides a liquid laundry detergent compositionwhich comprises from about 1 percent by weight to about 18 percent byweight, basis the total weight of the composition, of one or moresecondary alkyl sulfate compounds, from about 6 percent by weight toabout 38 percent by weight, basis the total weight of the composition,of one or more additional surfactant or cosurfactant compounds, fromabout 0 percent by weight to about 20 percent by weight, basis the totalweight of the composition, of one or more builders, and from about 35percent by weight to about 78 percent by weight, basis the total weightof the composition, of one or more solvents.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 represents the level of multisebum soil which can be removed byboth secondary alkyl sulfate-containing liquid laundry compositions andnon-secondary alkyl sulfate-containing liquid laundry compositions froma polyester/cotton fabric at a temperature of 60° F. and a waterhardness level of 300 parts per million.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention provides a liquid laundry detergent composition orformulation which comprises from about 1 percent by weight to about 18percent by weight, preferably from about 6 percent by weight to about 15percent by weight, basis the total weight of the composition, of one ormore secondary alkyl sulfate compounds, from about 6 percent by weightto about 38 percent by weight, preferably from about 6 percent by weightto about 18 percent by weight, basis the total weight of thecomposition, of one or more additional surfactant or cosurfactantcompounds, from about 0 percent by weight to about 20 percent by weight,preferably from about 4 percent by weight to about 12 percent by weight,basis the total weight of the composition, of one or more builders, andfrom about 35 percent by weight to about 78 percent by weight,preferably from about 40 percent by weight to about 60 percent byweight, basis the total weight of the composition, of one or moresolvents.

The secondary alkyl sulfate compounds serve as multifunctionalcomponents in the composition. Functioning as anionic surfactant, thepresence of these compounds aids in the removal of particulate and oilysoils. The secondary alkyl sulfate component further aids in providing adetergent composition which is tolerant to hard water wash applications.In addition, the secondary alkyl sulfate component aids in facilitatingthe suspension of soil in the washwater and its effective separationfrom laundered fabrics. These several functions of the secondary alkylsulfate compounds provide a very effective composition in terms of bothits detergent performance and physical properties.

The secondary alkyl sulfate compounds suitable for use in the liquidlaundry detergent composition of the present invention have the formula:##STR1## wherein R₂ represents an alkyl group having from about 3 toabout 18 carbon atoms, and R₃ represents an alkyl group having fromabout 1 to about 6 carbon atoms. In a preferred embodiment, R₂ is analkyl group having from about 10 to about 16 carbon atoms, and R₃ is analkyl group having from about 1 to about 2 carbon atoms. It is preferredthat R₂ and R₃ together are alkyl groups having a total of from about 11to about 17 carbon atoms. Preferred secondary alkyl sulfate compoundsinclude C₁₂ secondary alkyl sulfates (particularly those in which R₂ inthe above formula represents an alkyl group having 10 carbon atoms andR₃ in the above formula represents an alkyl group having 1 carbon atom),C₁₄ secondary alkyl sulfates (particularly those in which R₂ in theabove formula represents an alkyl group having 12 carbon atoms and R₃ inthe above formula represents an alkyl group having 1 carbon atom) C₁₆secondary alkyl sulfates (particularly those in which R₂ in the aboveformula represents an alkyl group having 14 carbon atoms and R₃ in theabove formula represents an alkyl group having 1 carbon atom), C₁₈secondary alkyl sulfates (particularly those in which R₂ in the aboveformula represents an alkyl group having 16 carbon atoms and R₃ in theabove formula represents an alkyl group having 1 carbon atom), andblends of these compounds. The secondary alkyl sulfate component of theheavy duty liquid compositions of the present invention typicallycomprises a C₁₄ secondary alkyl sulfate compound, although blends of oneor more C₁₄ secondary alkyl sulfate compounds and one or more C₁₈secondary alkyl sulfate compounds, and blends of one or more C₁₄secondary alkyl sulfate compounds, one or more C₁₆ secondary alkylsulfate compounds, and one or more C₁₈ secondary alkyl sulfate compoundsalso provide suitable liquid laundry compositions.

For enhanced biodegradability, it is preferred that the alkyl groups R₂and R₃ of the secondary alkyl sulfate molecule all be of predominantlylinear carbon chain structure. In this respect, it is particularlypreferred that the surfactant molecules be essentially free of alkylgroups having multiple branches in the carbon chain.

The secondary alkyl sulfate compound(s) suitable for use in the presentinvention is a solid, free-flowing powdered material which has a watercontent of less than about 3 percent by weight and which issubstantially free of diluents. These solid surface active compositionsare generally prepared by a crystallization technique. Specifically, thesolid secondary alkyl sulfate compositions are prepared by contacting adetergent range alkyl sulfuric acid-containing solution with a base inaqueous solution, removing substantially all of the water from themixture, cooling in the presence of a nonionic organic liquid diluent tocrystallize a solid secondary alkyl sulfate-containing surface activecomposition from the mixture, and recovering and drying the crystallizedsecondary alkyl sulfate product. The solid secondary alkyl sulfateproduct contains at least about 80 percent by weight to about 99 percentby weight of secondary alkyl sulfate. The product generally containssome residual level of sodium sulfate. The product typically containsless than about 12 percent by weight, preferably less than about 9percent by weight, of sodium sulfate.

The liquid detergent composition of the invention comprises from about 1to about 18 percent by weight of the secondary alkyl sulfate component.Compositions containing from about 6 to about 15 percent by weight ofthe secondary alkyl sulfate component are preferred, while compositionscontaining from about 9 percent by weight and about 13 percent by weightof the secondary alkyl sulfate component are particularly preferred.

The liquid laundry detergent also contains at least one or moreadditional surfactant or cosurfactant compounds. The additional orcosurfactant compound is selected from the group consisting of nonionicsurfactants, anionic surfactants, cationic surfactants, zwitterionicsurfactants and mixtures thereof. The additional or cosurfactantcompounds function as cleaning agents in the detergent composition ofthe present invention. In a preferred embodiment, it is preferred thatthe additional surfactant be one or more nonionic surfactants.

The nonionic surfactant or surfactants generally useful as additional orcosurfactant compounds in the present invention are the ethylene oxidecondensates (i.e., compounds produced by the condensation of ethyleneoxide groups which are hydrophilic in nature with an organic hydrophobiccompound which can be aliphatic or alkyl aromatic in nature) and thesugar-derived glycols (i.e., alkylpolyglycosides).

Particularly suitable nonionic surfactants are typically made up of oneor more ethylene oxide adducts, i.e. ethoxylates of alcohols oralkyl-substituted phenols, and can be represented by the formulaR--O--(CH₂ CH₂ O)_(n) --H, wherein the RO group corresponds to thestarting alcohol or alkyl-substituted phenol (less its active hydrogenatom). In general, the suitable alcohol ethoxylates are derived fromalcohols in the carbon range of from about 8 to about 18, while thesuitable alkyl phenol ethoxylates are derived from alkyl phenols havingalkyl substituents in the carbon range of from about 8 to about 2. Boththe alcohol ethoxylates and the alkyl phenol ethoxylates are nonionicsurfactants well known as components of conventional laundry detergentproducts.

With regard to the use of alcohol ethoxylate surfactants, the individualcompounds are preferably characterized by an alkyl R group in the carbonnumber range of from about 11 to about 15. Both primary and secondaryalcohol ethoxylates (having primary or secondary alkyl R groups,respectively) are suitable in the invention. The R group is suitablylinear or branched.

The alkyl-substituted phenol ethoxylate compounds preferably have analkyl substituent with between about 8 and about 11 carbon atoms. Thealkyl substituent may either be branched or linear.

Suitable nonionic ethoxylate surfactants typically contain an averagenumber of ethylene oxide units (i.e., an average value of n in the aboveformula) which is in the range of from about 3 to about 14 per molecule.Preferably, the ethoxylate surfactants contain an average number ofethylene oxide units which is in the range of from about 5 to about 9per molecule.

The sugar-derived glycols or alkyl glycosides which are useful asnonionic surfactants preferably have from about 6 to about 30 carbonatoms. Particularly suitable sugar-derived glycols are thealkylpolyglycosides.

Suitable anionic surfactants for use as additional surfactant orcosurfactant compounds in the liquid laundry detergent compositions ofthe present invention include the water-soluble, particularly the alkalimetal, ammonium and alkylammonium (e.g., monoethanolammonium,diethanolammonium or triethanolammonium) salts of organic sulfuric acidreaction products having in their molecular structure an alkyl groupcontaining from about 10 to about 20 carbon atoms and a sulfonic orsulfuric acid ester group. As used herein, the term "alkyl" alsoincludes the alkyl portion of aryl groups. Examples of anionic syntheticsurfactants include primary alkyl sulfates, especially those obtained bysulfating the higher alcohols (C₈ to C₁₈ s carbon atoms), andalkylbenzene sulfonates in which the alkyl group contains from about 9to about 15 carbon atoms in a straight chain or branched chainconfiguration.

Other suitable anionic surfactants which can be used in addition tosecondary alkyl sulfate in the liquid detergent composition include thewater-soluble salts of: paraffin sulfonates containing from about 8 toabout 24 carbon atoms; olefin sulfonates containing from about 8 toabout 24, preferably from about 12 to about 16 carbon atoms,particularly alpha olefin sulfonates; alkenyl or alkyl carboxysulfonatescontaining from about 8 to about 30 carbon atoms; alkylethoxycarboxylates containing from about 8 to about 24 carbon atoms andhaving from about 1 to about 10 units of ethylene oxide per molecule;alkyl glyceryl ether sulfonates derived from ethers of C₈ -C₁₈ alcohols;alkyl phenol ethoxysulfates containing from about 1 to about 10 units ofethylene oxide per molecule and from about 8 to about 12 carbon atoms inthe alkyl group; ethoxysulfates, i.e., alkyl ethylene oxide ethersulfates, containing from about 1 to about 10 units of ethylene oxideper molecule and from about 10 to about 15 carbon atoms in the alkylgroup; and soap. Especially suitable are water-soluble salts of alcoholethoxysulfates containing from about 1 to about 6 units of ethyleneoxide per molecule and from about 8 to about 18 carbon atoms in thealkyl group.

Other useful anionic surfactants include the water-soluble salts ofesters of alpha-sulfonated fatty acids containing from about 6 to about20 carbon atoms in the fatty acid group and from about 1 to about 10carbon atoms in the ester group; water-soluble salts of2-acyloxy-alkane-1-sulfonic acids containing from about 2 to about 9carbon atoms in the acyl group and from about 9 to about 23 carbon atomsin the alkane moiety; and beta-alkoxy alkane sulfonates containing fromabout 1 to about 3 carbon atoms in the alkyl group and from about 8 toabout 20 carbon atoms in the alkane moiety.

Preferred anionic surfactants for use as additional or cosurfactantcompounds are the alcohol ethoxysulfates which contain an average of upto about 6 ethylene oxide units per mole of alkyl sulfate.

Suitable zwitterionic surfactants for use as additional surfactant orcosurfactant compounds in the present composition include derivatives ofaliphatic quaternary ammonium, phosphonium, and sulfonium compounds inwhich the aliphatic moiety can be straight chain or branched chain andwherein one of the aliphatic substituents contains at least one anionicwater-solubilizing group. Examples of suitable zwitterionic surfactantsinclude 3-(N,N-dimethyl-N-hexadecylammonio) -propane-1- sulfonate andthe ammonium sulfonates and sulfates disclosed in U.S. Pat. Nos.3,925,262, issued Dec. 9, 1975 and 3,929,678, issued Dec. 30, 1975, theteachings of which are incorporated herein by reference.

Suitable cationic surfactants for use as additional or cosurfactantcompounds in the present liquid detergent composition include octadecyltrimethylammonium chloride, cetyl trimethylammonium methyl sulfate,polymeric cationics derived from monomers such as N,N,N-trimethyl-N-methylacryloxy (2-hydroxypropyl) ammonium chloride andcationic monomers such as those described in U.S. Pat. Nos. 4,212,820,issued on Jul. 15, 1980, 4,098,987, issued on Jul. 4, 1978, 4,171,418,issued on Oct. 16, 1979, and 4,426,489, issued Jan. 7, 1984, therelevant teachings of which are incorporated herein by reference. Inaddition to quaternary ammonium cationic moieties, the compounds withphosphonium, sulfonium, pyridium and isothiouronium moieties and thelike are also among the well known cationic surfactants.

The additional surfactant or cosurfactant compound(s) is typicallyutilized in the liquid laundry detergent composition in an amount offrom about 6 percent by weight to about 38 percent by weight, andpreferably in the range of from about 6 percent by weight to about 18percent by weight, basis the total weight of the liquid laundrydetergent composition.

The liquid laundry detergent composition of the present invention can,if desired, contain a detergent builder component. Builders are known tobe added to liquid detergent compositions to enhance cleaningperformance by softening water and providing alkalinity and bufferingcapacity to the wash. This builder component can either be of theorganic or inorganic type. The builder component is preferably one ormore materials selected from the group consisting of hydratable alkalimetal phosphates, alkali metal carbonates and bicarbonates (mixed orseparate, anhydrous or partially hydrated), zeolites (either crystallineor amorphous, and either natural or synthetic), ethylenediaminetetraacetate, nitrilotriacetate, and mixtures thereof. Carbonate andphosphate builders are particularly preferred. Examples of water-solubleinorganic builders which can be used, alone or in admixture withthemselves and organic alkaline builder salts, are alkali metalcarbonates, phosphates, polyphosphates, and silicates. Specific examplesof such salts are sodium tripolyphosphate, sodium carbonate, potassiumcarbonate, trisodium phosphate, tetrasodium pyrophosphate,tetrapotassium pyrophosphate, potassium tripolyphosphate, and sodiumhexametaphosphate. Examples of organic builder salts which can be usedalone, or in admixture with each other or with the preceding inorganicalkaline builder salts are alkali metal polycarboxylates, e.g.,water-soluble citrates such as sodium and potassium citrate, sodium andpotassium tartrate, the sodium and potassium salts of tartaric acidmonosuccinate, the sodium and potassium salts of tartaric aciddisuccinate, sodium and potassium ethylenediaminetetraacetate, sodiumand potassium N(2-hydroxyethyl)-ethylene diamine triacetates, sodium andpotassium nitrilo triacetates and sodium and potassiumN-(2-hydroxyethyl)-nitrilo diacetates. Other organic detergency builderssuch as water-soluble phosphonates can find use in the compositions ofthe invention. When the liquid laundry detergent contains a buildercomponent, the builder is generally present in an amount between about 0percent by weight and about 20 percent by weight, preferably in anamount between about 4 percent by weight and about 12 percent by weight,and most preferably between about 6 percent by weight and about 12percent by weight, basis the total weight of the liquid laundrydetergent composition.

The liquid laundry detergent composition may also contain analkanolamine component selected from the group consisting of anmonoethanolamine, diethanolamine, triethanolamine and mixtures thereof.Low levels of the alkanolamines, particularly monoethanolamine, arepreferred to enhance product stability, detergency performance, andodor. While the present compositions can contain mixtures of thealkanolamines, best color stability is obtained using singlealkanolamines. When the liquid laundry detergent contains analkanolamine component, such component is typically present in thecomposition in an amount in the range of from about 0 percent by weightto about 7 percent by weight, and preferably in an amount in the rangeof from about 1 percent by weight to about 4 percent by weight, basisthe total weight of the liquid laundry detergent composition.

The only other necessary component of the laundry liquid composition ofthe present invention is one or more solvents to aid in the blending ofthe surfactants and builder components, if present. The solvent may bewater or any other known solvent which aids in the blending ofsurfactants. Solvents other than water which are suitable include thelower alcohols such as, for example, ethanol, isopropanol, butanol,etc., the alkali metal aryl sulfonates such as, for example, sodiumxylenesulfonate, sodium cumenesulfonate, sodium toluenesulfonate, etc.,the polyols such as, for example, propylene glycol, hexylene glycol,etc., and the like and mixtures thereof. The solvent(s) is typicallypresent in the laundry liquid composition in an amount in the range offrom about 35 percent by weight to about 78 percent by weight, basis thetotal weight of the composition.

When a lower alcohol is used as a solvent, it is typically used incombination with at least one other solvent such as water, polyols, etc.The amount of lower alcohol utilized in the laundry liquid compositionis generally an amount in the range of from about 0.1 percent by weightto about 7 percent by weight, basis the total weight of the composition.

Any polyol containing from about 2 to about 6 carbon atoms and from 2 toabout 6 hydroxy groups can be used as a solvent in the laundry liquidcompositions of the present invention. Examples of such polyols areethylene glycol, propylene glycol, hexylene glycol and glycerine.Propylene glycol is particularly preferred. When a polyol is used as asolvent, the polyol typically is used in combination with at least oneother solvent and represents from about 0.1 percent by weight to about 8percent by weight, basis the total weight of the detergent composition.

In a preferred embodiment, the solvent is water or a water-containingsolvent system. The laundry liquids generally contain from about 25percent by weight to about 73 percent by weight, preferably from about40 percent by weight to about 60 percent by weight, basis the totalweight of the composition, of water. A particularly suitablewater-containing solvent system contains water, ethanol and one or morepolyols.

In addition to its principal components, secondary alkyl sulfate,additional surfactant, and solvent, the liquid laundry detergentcomposition may suitably contain minor amounts of other components knownin the art for use in laundry liquids. Non-limiting examples of suchcomponent include dyes, fragrances, bleaches, bleach activators,enzymes, viscosity modifiers, and the like. The amount of thesecomponents present in the liquid detergent composition will typically beless than about 7 percent by weight, and preferably less than about 3percent by weight, basis the total weight of the composition.

The principal components of the liquid detergent composition aresuitably blended into the finished composition by conventional methodsfor the preparation of liquid detergent compositions, for instance, bydirect mixing/blending. In a preferred embodiment, the liquid laundrydetergent composition contains from about 6 percent by weight to about15 percent by weight, basis the total weight of the composition, of asecondary alkyl sulfate compound having a carbon number in the range offrom about 12 to about 18, from about 6 percent by weight to about 18percent by weight, basis the total weight of the composition, of atleast one additional surfactant, from about 4 percent by weight to about12 percent by weight, basis the total weight of the composition, of abuilder, and from about 40 percent by weight to about 60 percent byweight, basis the total weight of the composition, of a solvent.

The ranges and limitations provided in the instant specification andclaims are those which are believed to particularly point out anddistinctly claim the present invention. It is, however, understood thatother ranges and limitations which perform substantially the samefunction in substantially the same manner to obtain the same orsubstantially the same result are intended to be within the scope of thepresent invention as defined by the specification and claims.

The invention is further described with reference to the followingexamples, which are intended to illustrate certain aspects of theinvention, without limiting its broader scope.

ILLUSTRATIVE EMBODIMENTS Example 1

49 Grams of water were added to the mixing vessel and warmed to 90° F.(38° C.). 2 Grams of ethanol, 2 grams of monoethanolamine and 4 grams ofpropylene glycol were then added. 12.1 Grams of C₁₄ secondary alkylsulfate (SAS) (sodium salt, 99% active powder) was then added to themixing vessel. 10 Grams of C₁₂ -C₁₅ alcohol ethoxysulfate having anaverage of three ethylene oxide units per molecule (AES) (sodium salt,60% active) was then added and the mixture was allowed to mix well. 6Grams of C₁₂ -C₁₃ alcohol ethoxylate having an average of 6.5 ethyleneoxide units per molecule (AE) was thereafter added and the mixture wasallowed to stir. The temperature was then raised to 110°-120° F.(43°-39° C.). Following the temperature increase, 2 grams of coconutfatty acid, 8 grams of citric acid and 5 grams of sodium hydroxide (50%solution) were added to the mixture. The resulting material was a clearstable liquid. The properties of the composition prepared are presentedin Table I and FIG. 1.

Example 2

49 Grams of water were added to the mixing vessel and warmed to 90° F.(38° C.). 2 Grams of ethanol, 2 grams of monoethanolamine and 4 grams ofpropylene glycol were then added. 7.3 Grams of C₁₄ secondary alkylsulfate (SAS) (sodium salt, 99% active powder) and 4.8 grams of C₁₈secondary alkyl sulfate (SAS) (sodium salt, 99% active powder)were thenadded to the mixing vessel. 10 Grams of C₁₂ --C₁₅ alcohol ethoxysulfatehaving an average of three ethylene oxide units per molecule (AES)(sodium salt, 60% active) was then added and the mixture was allowed tomix well. 6 Grams of C₁₂ --C₁₃ alcohol ethoxylate having an average of6.5 ethylene oxide units per molecule (AE) was thereafter added and themixture was allowed to stir. The temperature was then raised to110°-120° F. (43°-39° C.). Following the temperature increase, 2 gramsof coconut fatty acid, 8 grams of citric acid and 5 grams of sodiumhydroxide (50% solution) were added to the mixture. The resultingmaterial was a clear stable liquid. The properties of the compositionprepared are presented in Table I and FIG. 1.

Comparative Example A

Comparative Example A was carried out in a manner similar to Example 1,except that 41 grams of water were used and 20 grams of C₁₂ linearalkylbenzene sulfonate (LAS) (sodium salt, 99% active) were used inplace of the secondary alkyl sulfate component, The properties of thecomposition prepared are presented in Table I and FIG. 1.

Example 3

42.4 Grams of water wore added to the mixing vessel and warmed to 90° F.(38° C.). 2 Grams of ethanol, 2 grams of monoethanolamine and 4 grams ofpropylene glycol were then added. 12.1 Grams of C₁₄ secondary alkylsulfate (sodium salt, 99% active powder) was then added to the mixingvessel. 16.6 Grams of C₁₂ -C₁₅ alcohol ethoxysulfate having an averageof three ethylene oxide units per molecule (sodium salt, 60% active) wasthen added and the mixture was allowed to mix well. 6 Grams of C₁₂ -C₁₃alcohol ethoxylate having an average of 6.5 ethylene oxide units permolecule was thereafter added and the mixture was allowed to stir. Thetemperature was then raised to 110°-120° F. (43°-39° C.). Following thetemperature increase, 2 grams of coconut fatty acid, 8 grams of citricacid and 5 grams of sodium hydroxide (50% solution) were added to themixture. The resulting material was a clear stable liquid. Theproperties of the composition prepared are presented in Table I and FIG.1.

Comparative Example B

Comparative Example B was carried out in a manner similar to Example 3,except that 34.4 grams of water were used and 20 grams of C₁₂ linearalkylbenzene sulfonate (LAS) (sodium salt, 60% active) were used inplace of the secondary alkyl sulfate component. The properties of thecomposition are presented in Table I and FIG. 1.

Comparative Example C

Comparative Example C was carried out in a manner similar to Example 3,except that 25.5 grams of water were used and 28.9 grams of C₁₄ -C₁₅primary alkyl sulfate (PAS) (sodium salt, 17.3% active) were used inplace of the secondary alkyl sulfate component, The properties of thecomposition prepared are presented in Table I and FIG. 1.

Example 4

42.4 Grams of water were added to the mixing vessel and warmed to 90° F.(38° C.). 2 Grams of ethanol, 2 grams of monoethanolamine and 4 grams ofpropylene glycol were then added. 12.1 Grams of C₁₄ secondary alkylsulfate (sodium salt, 99% active powder) was then added to the mixingvessel. 6 Grams of C₁₂ -C₁₅ alcohol ethoxylate having an average of nineethylene oxide units per molecule was then added and the mixture wasallowed to mix well. 16.6 Grams of C₁₂ -C₁₃ alcohol ethoxysulfate havingan average of three ethylene oxide units per molecule (sodium salt, 60%active) was thereafter added and the mixture was allowed to stir. Thetemperature was then raised to 110°-120° F. (43°-39° C.). Following thetemperature increase, 2 grams of coconut fatty acid, 8 grams of citricacid and 5 grams of sodium hydroxide (50% solution) were added to themixture. The resulting material was a clear stable liquid. Theproperties of the composition prepared are presented in Table I and FIG.1.

Example 5

42.4 Grams of water were added to the mixing vessel and warmed to 90° F.(38° C.). 2 Grams of ethanol, 2 grams of monoethanolamine and 4 grams ofpropylene glycol were then added. 4.8 Grams of C₁₄ secondary alkylsulfate (sodium salt, 99% active powder), 6.1 grams of C₁₆ secondaryalkyl sulfate (sodium salt, 99% active powder), and 1.2 grams of C₁₈secondary alkyl sulfate (sodium salt, 99% active powder) were then addedto the mixing vessel. 6 Grams of C₁₂ -C₁₅ alcohol ethoxylate having anaverage of nine ethylene oxide units per molecule was then added and themixture was allowed to mix well. 16.6 Grams of C₁₂ -C₁₃ alcoholethoxysulfate having an average of three ethylene oxide units permolecule (sodium salt, 60% active) was thereafter added and the mixturewas allowed to stir. The temperature was then raised to 110°-120 F.(43°-39 ° C.). Following the temperature increase, 2 grams of coconutfatty acid, 8 grams of citric acid and 5 grams of sodium hydroxide (50%solution) were added to the mixture. The resulting material was a clearstable liquid. The properties of the composition prepared are presentedin Table I and FIG. 1.

Comparative Example D

Comparative Example D was carried out in a manner similar to Example 4,except that 34.4 grams of water were used and 20 grams of C₁₂ linearalkylbenzene sulfonate (LAS) (sodium salt, 60% active) were used inplace of the secondary alkyl sulfate component. The properties of thecomposition prepared are presented in Table I and FIG. 1.

Discussion of the Results and Detailed Description of the Drawing

As can be seen in Table I and FIG. 1, the level of soil removal obtainedwith secondary alkyl sulfate-containing heavy duty laundry liquids(Examples 1-5) is much higher than that obtained with heavy duty laundryliquids containing LAS (Comparative Examples A, B and D) and with heavyduty laundry liquids containing PAS (Comparative Example C).

                                      TABLE I                                     __________________________________________________________________________    SECONDARY ALKYLSULFATES (SAS) IN HEAVY DUTY LIQUIDS (HDL's)                   Component, % wt                                                               Basis 100% active unless                                                                  Ex.                                                                              Ex.                                                                              Comp.                                                                             Ex.                                                                              Comp.                                                                             Comp.                                                                             Ex.                                                                              Ex.                                                                              Comp.                                  otherwise indicated                                                                       1  2  Ex. A                                                                             3  Ex. B                                                                             Ex. C                                                                             4  5  Ex. D                                  __________________________________________________________________________    C.sub.14 SAS                                                                              12 7.2                                                                              --  12 --  --  12 4.8                                                                              --                                     C.sub.16 SAS                                                                              -- -- --  -- --  --  -- 6  --                                     C.sub.18 SAS                                                                              -- 4.8                                                                              --  -- --  --  -- 1.2                                                                              --                                     C.sub.12 LAS (60%)                                                                        -- -- 20  -- 20  --  -- -- 20                                     C.sub.14-15 PAS (17.3)                                                                    -- -- --  -- --  28.9                                                                              -- -- --                                     C.sub.12-13 EO.sub.3 S (60%)                                                              10 10 10  16.6                                                                             16.6                                                                              16.6                                                                              16.6                                                                             16.6                                                                             16.6                                   C.sub.12- 13 EO.sub.6.5                                                                   6  6  6   6  6   6   -- -- --                                     C.sub.12-15 EO.sub.9                                                                      -- -- --  -- --  --  6  6  6                                      Coconut Fatty Acid                                                                        2  2  2   2  2   2   2  2  2                                      Citric Acid 8  8  8   8  8   8   8  8  8                                      Monoethanolamine                                                                          2  2  2   2  2   2   2  2  2                                      Propylene glycol                                                                          4  4  4   4  4   4   4  4  4                                      Sodium Hydroxide                                                                          5  5  5   5  5   5   5  5  5                                      (50%)                                                                         Ethanol     2  2  2   2  2   2   2  2  2                                      Water       49 49 41  42.4                                                                             34.4                                                                              25.5                                                                              42.4                                                                             42.4                                                                             34.4                                   Detergency.sup.a)                                                                         36.8                                                                             32.0                                                                             24.7                                                                              39.5                                                                             28.2                                                                              31.8                                                                              40.5                                                                             39.4                                                                             29.8                                   __________________________________________________________________________     .sup.a) Temperature 60° F., 300 ppm water hardness. Radiolabeled       sebum soil removal from permanent press (65/35) polyester/cotton was          determined as described in "Detergency. Theory and Technology", G. W.         Cutler and E. Kissa, eds., Surfactant Science Series, Vol. 20, p. 125         (1987) and N. Prieto, J. Am. Oil Chem. Soc. 66 10 (1989). All examples an     comparative examples were tested at a dose of 2 grams/liter. Results are      expressed as percent soil removal.                                       

What is claimed is:
 1. A liquid laundry detergent composition comprisingfrom about 1 percent by weight to about 18 percent by weight, basis thetotal weight of the composition, of one or more secondary alkyl sulfatecompounds, from about 6 percent by weight to about 38 percent by weight,basis the total weight of the composition, of one or more cosurfactantcompounds, from about 0 percent by weight to about 20 percent by weight,basis the total weight of the composition, of one or more builders, andfrom about 35 percent by weight to about 78 percent by weight, basis thetotal weight of the composition, of one or more solvents.
 2. Thecomposition of claim 1 wherein said one or more secondary alkyl sulfatecompounds has a formula: ##STR2## wherein R₂ represents an alkyl grouphaving from about 3 to about 18 carbon atoms and R₃ represents an alkylgroup having from about 1 to about 6 carbon atoms.
 3. The composition ofclaim 2 wherein said one or more secondary alkyl sulfate compounds isselected from the group consisting of a C₁₂ secondary alkyl sulfatewherein R₂ represents an alkyl group having 10 carbon atoms and R₃represents an alkyl group having 1 carbon atom, a C₁₄ secondary alkylsulfate wherein R₂ represents an alkyl group having 12 carbon atoms andR₃ represents an alkyl group having 1 carbon atom, a C₁₆ secondary alkylsulfate wherein R₂ represents an alkyl group having 14 carbon atoms andR₃ represents an alkyl group having 1 carbon atom, a C₁₈ secondary alkylsulfate wherein R₂ represents an alkyl group having 16 carbon atoms andR₃ represents an alkyl group having 1 carbon atom, and mixtures of thesecompounds.
 4. The composition of claim 1 wherein the secondary alkylsulfate compound is added to the composition in the form of a freeflowing powder.
 5. The composition of claim 1 wherein the secondaryalkyl sulfate compound is present in the composition in an amount offrom about 6 percent by weight to about 15 percent by weight, basis thetotal weight of the composition.
 6. The composition of claim 1 whereinsaid one or more builders is selected from the group consisting ofalkali metal carbonates, alkali metal phosphates, alkali metalpolyphosphates, alkali metal silicates, alkali metal bicarbonates,alkali metal polycarboxylates, polyacrylates and mixtures thereof. 7.The composition of claim 6 wherein said one or more builders is analkali metal polycarboxylate.
 8. The composition of claim 7 wherein saidalkali metal polycarboxylate is selected from the group consisting ofsodium citrate, potassium citrate, the sodium salt of tartaric acidmonosuccinate, the potassium salt of tartaric acid monosuccinate, thesodium salt of tartaric acid disuccinate, the potassium salt of tartaricacid disuccinate, and mixtures thereof.
 9. The composition of claim 1wherein said builder is present in an amount of from about 4 percent byweight to about 12 percent by weight, basis the total weight of thecomposition.
 10. The composition of claim 1 wherein said one or morecosurfactant compounds is selected from the group consisting of anionicsurfactants, nonionic surfactants, cationic surfactants, zwitterionicsurfactants, and mixtures thereof.
 11. The composition of claim 1wherein said one or more cosurfactant compounds is selected from thegroup consisting of anionic surfactants, nonionic surfactants, andmixtures thereof.
 12. The composition of claim 11 wherein said one ormore cosurfactant compounds is a nonionic surfactant selected fromalcohol ethoxylates having an average of from about 3 to about 14ethylene oxide units per ethoxylate molecule, alkyl-substituted phenolethoxylates having an average of from about 3 to about 14 ethylene oxideunits per ethoxylate molecule, sugar-derived glycols, and mixturesthereof.
 13. The composition of claim 1 wherein said compositioncomprises from about 6 percent by weight to about 8 percent by weight,basis the total weight of the composition, of said one or morecosurfactant compounds.
 14. The composition of claim 1 wherein said oneor more solvents is selected from the group consisting of water, loweralcohols, polyols, alkali metal aryl sulfonates and mixtures thereof.15. The composition of claim 14 wherein said one or more solventscomprises a mixture of a lower alcohol, water, and a polyol.
 16. Thecomposition of claim 1 wherein said composition comprises from about 40percent by weight to about 60 percent by weight, basis the total weightof the composition, of one or more solvents.
 17. A liquid laundrydetergent composition comprising from about 6 percent by weight to about15 percent by weight, basis the total weight of the composition, of oneor more secondary alkyl sulfate compounds, from about 6 percent byweight to about 18 percent by weight, basis the total weight of thecomposition, of one or more cosurfactant compounds, from about 4 percentby weight to about 12 percent by weight, basis the total weight of thecomposition, of one or more builders, and from about 40 percent byweight to about 60 percent by weight, basis the total weight of thecomposition, of one or more solvents.